Muscle Soreness and Recovery from Exercise

Muscle soreness is the most common side effect of exercise that some might seek or, opposite, might stop regular strength training. Some think, “If I have to feel like this every time, this is going to suck or ruin my other active hobbies.”

Here is some information about what muscle soreness is caused by, how you can prevent it while still making gains, a quick summary of the recovery methods that are worth the time, and how to use soreness to guide your training. This blog is not about joint soreness but the feeling of soreness or general pain around a broad area of a muscle (often the lower body muscles Localisation of damage in the human leg muscles induced by downhill running - PMC) which peaks 1-2 days “new” post-exercise and then settles within a couple more days.

"What causes muscle soreness?"

Many believe muscle soreness is due to a kind of “microscopic muscle damage.” However, that is not the most supported hypothesis. We do not have the technology to measure microscopic muscle changes (just large changes such as an MRI for muscle injuries) MR imaging-guided muscle biopsy for correlation of increased signal intensity with ultrastructural change and delayed-onset muscle soreness after exercise - PubMed. Blood markers that have the best correlation to “exercise-induced muscle damage” are not highest when muscle soreness is highest. Muscle damage is still measurable even when soreness has reduced a week after the exercise that caused the initial soreness Myofibre damage in human skeletal muscle: effects of electrical stimulation versus voluntary contraction - PMC Also, when tested properly, strength can still be high/normal in those with soreness suggesting soreness is definitely only “microscopic” and not significant enough to cause weakness like macroscopic muscle damage might. Delayed-onset muscle soreness does not reflect the magnitude of eccentric exercise-induced muscle damage - PubMed 

The most evidence-based theory is that muscle soreness is caused by immune activity (including pathways involved in “inflammation”) affecting the nerves and connective tissue within and around the muscles, rather from the muscle directly. Delayed onset muscle soreness: Involvement of neurotrophic factors - PubMed +  The role of Ca2+ in muscle cell damage - PubMed + Exercise-induced oxidative stress in humans: cause and consequences - PubMed + Is “Delayed Onset Muscle Soreness” a False Friend? The Potential Implication of the Fascial Connective Tissue in Post-Exercise Discomfort + What causes delayed onset muscle soreness (DOMS)? | by Chris Beardsley | Medium + Re-Evaluation of Sarcolemma Injury and Muscle Swelling in Human Skeletal Muscles after Eccentric Exercise - PMC + Review of the Repeated Bout Effect in Trained and Untrained men + Exogenously Applied Muscle Metabolites Synergistically Evoke Sensations of Muscle Fatigue and Pain in Human Subjects - PMC However, not all the "inflammation" observed in this post-exercise response is the specific cause, explaining why oral "anti-inflammatory" medication is not strongly helpful for reducing muscle soreness after exercise. Also, the “inflammatory response” to exercise does not decrease in accustomed exercise, whereas post-muscle soreness does.  Immunological changes in human skeletal muscle and blood after eccentric exercise and multiple biopsies - PMC + Leukocytes, cytokines, growth factors and hormones in human skeletal muscle and blood after uphill or downhill running - PubMed + Influence of a prostaglandin-inhibiting drug on muscle soreness after eccentric work - PubMed + Skeletal Muscle Inflammation Following Repeated Bouts of Lengthening Contractions in Humans - PubMed + The effect of training status on the serum creatine kinase response, soreness and muscle function following resistance exercise - PubMed 

Assessing these facts indicates that the jury is still out on what is really causing muscle soreness. Always be sceptical of strong opinions otherwise. It's mostly likely that a lot of known and unknown factors contribute, but it is not primarily “muscle damage,” as so many used to believe, which is helpful to remove fear moving and training with muscle soreness.

“So, is post-workout muscle soreness a good or bad indicator of a signal of maximal muscle growth and strength? Is more than better than less?”

More soreness will not equal more muscle growth occurring. You would not run a marathon to grow as much muscle or get as strong as possible, despite significant soreness you would feel days (to weeks) after completion. We make the case for small to moderate amounts of soreness after strength training as a helpful but not the best or only long-term tracker for completing enough training to make consistent long-term muscle growth gains.

The best evidence of muscle growth is the increased ability to lift more weight with consistent form throughout 6-12 repetitions over months. If your total weight lifted in that rep range is increasing over months of the same exercise, you are likely growing muscle regardless of the amount of soreness post-training. Small to moderate soreness after training for muscle growth, particularly when you complete a new exercise, can be considered a positive sign that the muscle growth training stimulus was enough to initiate muscle growth but not as a “the more, the better” relationship. However, don't panic if you are not sore after a session as:

1.     Soreness will vary across body parts between different individuals,

2.     Soreness is not a perfect correlate of muscle changes occurring,

3.     It does not need to occur for you to get still stronger if that is a goal compared to just muscle growth.

4.     Muscle soreness is not the best evidence for muscle growth occurring as more muscle soreness does not correlate with more muscle growth over time.

5.     We know muscle growth occurs long-term when even progressive lifting dosages stops causing soreness

6.     Resistance training contraction modes like isometrics (a plank for the core) or isotonic (sits ups for the core) modes when progressed over time, all contribute to similar degrees of muscle growth, but isotonic muscle contractions often will cause more soreness than isometrics The development of skeletal muscle hypertrophy through resistance training: the role of muscle damage and muscle protein synthesis - PubMed

A more complex point for those concerned with growing muscle for aesthetic rather than health reasons is that muscle soreness is not a good indicator of a measure of muscle metabolism called “muscle protein synthesis”. However, as well, it was once thought that higher and more frequent muscle protein synthesis response post-exercise per week predicted more muscle growth potential, but this also has yet to be strongly supported by evidence  An Evidence-Based Narrative Review of Mechanisms of Resistance Exercise–Induced Human Skeletal Muscle Hypertrophy - PMC + Stimuli and sensors that initiate skeletal muscle hypertrophy following resistance exercise | Journal of Applied Physiology .

The current information suggests not aiming for large amounts of soreness post-workout but for a long-term, sustainable, small to moderate amount if your goal is muscle growth. Slight to moderate amounts of soreness are a consequence of optimally difficult, sustainable (or repeatable) progressive resistance training that is needed to grow muscle long-term. 

"What about other fitness goals independent of muscle growth?”

For running or other aerobic sports like swimming, cycling, or team field events, soreness is a less helpful marker in these contexts than after muscle growth training. Fatigue and mild soreness of joint “awareness” are expected after these exercise modes but should not be sought even to a small or moderate amount, as you would if muscle growth was your goal. 

Instead, soreness is best avoided if you train regularly each week and your goal is strength or maximal performance each weekend, such as for athletes. This is not because soreness reduces true strength or skill but instead because it reduces readiness to train and increases the perception of weakness. These impacts are not helpful and should be kept low long-term for consistent training benefits in this context. Aim to avoid soreness as much as practical to maintain a high readiness to train hard. Apart from resistance training after your sports session, read the next section for the best ways to strength train and avoid soreness that might affect your readiness to train during your precious sports training sessions. 

For those with any fitness goal, here are our tips to reduce the chance of moderate to severe soreness (assuming you are doing enough exercise to elicit adaptations)

• Prevention is easier by:

  • Avoid resistance training to the point where you are only 4-5 repetitions away from momentary movement failure (when you can't complete the movement through the full range of motion). Instead, keep more repetitions "in the tank." Lower the total number of repetitions per set. Each challenging set should be less than 6 repetitions long, as this is less likely to cause soreness.

  • Keep total working sets to 1 to 2 sets.

  • Increase rest periods between sets.

  • Do the same exercises as the last session. 

  • Making weekly to monthly progression of total session volume per muscle group (sets x reps x weight) less than what has made you sore previously. What is “less” depends on how you previously progressed you’re training each week to month, so no universal number or percentage change can be given. Individual coaching will help guide you here.

  • Contraction modes like isometrics (like planks for the core) induce less muscle soreness than dynamic movements (like sit-ups for the core).

  • Despite their social popularity, massage, foam rolling, and stretching do not have strong evidence to suggest they prevent muscle soreness when completed prior to exercise. They might help reduce symptoms when you are already sore, but this is also not consistent for all individuals and is not greatly better than time and any enjoyable movement, so you are not missing out if you do not complete them.

When we first complete exercise, after a couple of weeks off or completing a new exercise, we tend to have the most soreness response. The mistake is to think this is what it will feel like every time. It will not. Over time, you will likely not have as much soreness each time you complete the same quantity of exercise that made you sore before. 

“Okay, I am sore. Now what?”

If you are already sore, following the best ‘bang-for-buck’ recovery tactics can help you tolerate subsequent movement. Remember that reducing soreness does not mean you are speeding up recovery but purely reducing muscle sensitivity to movement. These “big buck” tactics, in order of importance or effectiveness, include: 

1.     Getting a high-quality sleep consistently and for long enough Sleep and muscle recovery: endocrinological and molecular basis for a new and promising hypothesis - PubMed. See this article for more https://www.methodhealth.com.au/post/sleep-health-and-habits 

2.     Complete 10-15 min of any low-intensity aerobic exercise or 2-3 sets of lighter-intensity strength sets before completing your working sets.

3.     Reduce as much mental and social stress as realistically possible Chronic psychological stress impairs recovery of muscular function and somatic sensations over a 96-hour period - PubMed + https://pmc.ncbi.nlm.nih.gov/articles/PMC5546756/ 

4.     Nutrition tactics like making sure you are consuming enough energy with a less important emphasis on consuming food groups, including fruit, vegetable and proteins (animal or plant-based). Aim across the whole week (rather than just around your exercise sessions) to maintain a diet filled with a variety of daily proteins, fruit and vegetables that maintain your bodyweight and you shouldn’t need any “recovery” supplement long term. However, the associated supplemental forms of protein, fruit and vegetable such as vitamin or mineral tablets/creams, protein powders or collagen, fish oil tablets all have some (but weak) evidence to suggest helpfulness for soreness. This might be because these supplements are aimed at reducing “muscle damage,” but as explained at the start of this article, is not perfectly correlated to muscle soreness. Weekly Lesson - ANTIOXIDANT SUPPLEMENTS IN SPORTS NUTRITION - Anniversary 2020 +Antioxidants for preventing and reducing muscle soreness after exercise: a Cochrane systematic review - PubMed + Fruit supplementation reduces indices of exercise-induced muscle damage: a systematic review and meta-analysis - PubMed  + The short-term effect of high versus moderate protein intake on recovery after strength training in resistance-trained individuals | Journal of the International Society of Sports Nutrition | Full Text + Weekly Lesson - Exercise and Nutrition to Support Muscle Health in Older Adults - Virtual 2021 + Impact of Collagen Peptide Supplementation in Combination with Long-Term Physical Training on Strength, Musculotendinous Remodeling, Functional Recovery, and Body Composition in Healthy Adults: A Systematic Review with Meta-analysis | Sports Medicine + The short-term effect of high versus moderate protein intake on recovery after strength training in resistance-trained individuals - PubMed

For those seeking physiotherapy support, many of these recovery principles will also reduce joint, muscle, or tendon pain levels. These “recovery tactics” all help improve your immune system health which reduces any impact low-grade persistent systemic inflammation induced by poor general health and stress might have on increasing sensitivity to movement. Signalling at neuro/immune synapses - PMC + The contribution of neuro-immune crosstalk to pain in the peripheral nervous system and the spinal cord - ScienceDirect + Role of Peripheral Immune Cells for Development and Recovery of Chronic Pain - PubMed + Predicting Recurrent Care Seeking of Physical Therapy for Musculoskeletal Pain Conditions - PubMed

Other recovery tactics popularly used aren’t predictably helpful over the small to moderate effects of a placebo. Nil to minimal effects have been found for recovery using highly alluring and socially popular “recovery” methods, including massage, stretching, pneumatic compression devices, ice baths, and hot baths/showers, which all might not be as effective as a placebo, so make sure you are not completing these over other often over-promising recovery “hacks” or “secrets”. The Effects of Intermittent Pneumatic Compression on the Reduction of Exercise-Induced Muscle Damage in Endurance Athletes: A Critically Appraised Topic - PubMed + Putting the Squeeze on Compression Garments: Current Evidence and Recommendations for Future Research: A Systematic Scoping Review - PubMed + Ice or Heat for Pain and Injuries? - E3 Rehab + Mechanisms and efficacy of heat and cold therapies for musculoskeletal injury - PubMed + + Effects of Cold-Water Immersion Compared with Other Recovery Modalities on Athletic Performance Following Acute Strenuous Exercise in Physically Active Participants: A Systematic Review, Meta-Analysis, and Meta-Regression - PubMed + The Effects of Regular Cold-Water Immersion Use on Training-Induced Changes in Strength and Endurance Performance: A Systematic Review with Meta-Analysis | Sports Medicine + The Effects of Massage Guns on Performance and Recovery: A Systematic Review - PubMed + Effect of sports massage on performance and recovery: a systematic review and meta-analysis - PubMed + The Effects of Massage Therapy on Sport and Exercise Performance: A Systematic Review + Massage Therapy Does Not Work by "Increasing Circulation" 

“Is training with muscle soreness safe?"

Training with muscle soreness is very safe. As we have described in the first section, soreness is not linked to what might be labelled as observable muscle damage with medical imaging, so it is very safe to train your muscles when sore, although, yes, it does not feel amazing initially. This is why prevention is easier than the cure. Often, soreness lasts longer than when your muscles are ready to respond to the stimulus of strength training, so you should not wait for all soreness to reduce if you want to progress in your exercise quickly across weeks to months.

Muscle soreness should be distinguished from “niggles” or new, more minor sore spots around the muscle or joint, which has been shown to be a potential predictor of future injury risk in athletes, so is a good feeling to monitor with independent guidance optimistically as part of good injury risk reduction practices Do Niggles Matter? - Increased injury risk following physical complaints in football (soccer): Science and Medicine in Football. Our physiotherapists at Method Health can help you with that, so book a session to chat about all things recovery from your weekly exercise or sports habits and rule out any injuries that mean you might need help modifying your weekly exercise and active hobbies.